Combination rolling and scraping cutter bit



R. W. SCH LUMPF COMBINATION ROLLING AND SCRAPING CUTTER BIT Filed July21, 1950 Sept. 27, 1932.

Patented Sept. 27, 1932 UNITED STATES ROBERT W. SCHLUIPI, OF HOUSTON,TEXAS, ASSIGNOR'TO HUGHES TOOLCOMPANY,

OI HOUSTON, TEXAS, A CORPORATION OF-TEXAS P oomanu'rron ROLLING ANDsoaarmcr our'raa 31m. 1

Application filed July 21,

My invention relates to earth boring drills to be employed in deep welldrilling for oil, gas, sulphur, and the like.

In drilling deep wells, it is found in some localities that theformation through which the drill is advancing is composed of varyingmaterials, some of which are soft and plastic, and others hard andbrittle. It is difiicult with the roller drill to provide a cutter whichwill cut all kinds of formations, and thus enable the driller tocontinue drilling with the same drill through all the formations whichhe encounters.

It is an object of my invention to provide a drill having cuttersthereon, arranged and formed to drill through all types of formations. i

I desire to provide both rolling and scraping cutters upon the samedrill, so arranged that the scraping cutter will cut off the materialloosened from the bottom of the hole by the rolling cutter.

As a further object I provide a drill in which the cutters may bereadilyassembled thereon without ditficulty.

In the drawing herewith I have shown in Fig. 1 a side elevation of adrill embodying my invention.

Fig. 2 is a side view taken at right angles to the view shown in Fig. 1.

Fig. 3 is a bottom plan view of the drill.

My drill comprises a head 1 ofapproximately cylindrical shape at itsupper end and provided with a threaded shank 2 for engagement with thedrill collar or tool joint. Below the cylindrical portion 1, the head isflattened somewhat and is provided with two diverging arms 3 and 4. Thearm 3 being shaped to receive the rolling cutter 5, and the arm 4 toreceive the scraping cutter 6. The rolling cutter 5 is of ordinaryconstruction now common in the art. Itis approximately frusto-conical inshape, and is mounted in an inclined position so that it will have anapproximately true rolling motion as it rolls upon the bottom of thehole.

The scraping cutter is mounted opposite the rolling cutter 5. Thescraping cutter 6 comprises a blade, the flattened upper end 1930.SerialNo. 469,301. a

P NT 10mm 7 of which fits within a slot or recess 8 formedlongitudinally of the farm 4. The blade is held in position in therecess 8 by transverse bolts or screws 9 extended through said arm andsaid blade, and held against unscrewing by'cotter pins 10 thereon. Theblade6 is curved forwardly in the direction ofrotationat its outer endand istapered to a cutting edge 12. I v As seen from Fig. 3, it will beunderstood that the blade is curved forwardly to a greatchannel conductswater axially of the head and discharges it upon the two cuttingelements thus described. I

In the use of my improved drill, it is found that even in the hardformation, the rolling cutter 5 will penetrate into the formation,leaving a corrugated bottom to the hole. The

scraping cutter will engage upon the crests of the corrugations formedbythe rolling cutter and tend to remove them, so that they may becarried away with the flushing fluid. This is particularly true in caseof plastic or soft formations into which the teeth of the rolling cuttermay penetrate deeply but in which the material is not chipped ordisintegrated upon the bottom of the hole.

The arrangement of the two cutters in opposite relation as shownproduces a particularly effective and well balanced drill in which thetwo cutters cooperate to remove the material'from the well bottomwithout difliculty. e

The advantages of this structure 'will be apparent without furtherdescription.

What I claim as new is:'

1. An earth boring drill including a head, a pair of downwardlyprojecting arms thereon, an approximately frusto-conical rolling cuttermounted upon one of saidarms, and

a flattened scraping blade secured upon the other of said arms".

2. An earth boring drill inclg'ding a head,

a pair of downwardly projecting arms thereon, an approximatelyfrusto-conical rollin cutter mounted upon one of said arms, an aflattened scraping blade secured upon the other of said arms, saidcutters being arranged in balanced position opposite each other at theforward end of said head.

3. An earth boring drill including a head, a downwardly and outwardlyinclined arm at the forward end thereof, a frusto-conical shaped cuttermounted thereon to engagethe bottom of the hole with an approximatelytrue rolling action, and a scraping blade positioned opposite'saidrolling cutter and adapted to cut the material engaged by said rollingcutter. y

4. An earth boring drill including a head, a downwardly and outwardlyinclined arm at the forward end thereof, a frusto-conical shaped cuttermounted thereon to engage the bottom of thehole with an approximatelytrue rolling action, a flattened forwardly extending arm opposite saidcutter, and a blade secured detachably in said arm, said blade beingrigidly positioned slightly above said rolling cutter to cut thematerial loosened by said rolling cutter.

In testimony whereof, I hereunto affix my signature, this the 16 day ofJuly A. 1).,

1930. Y Y ROBERT W. SCHLUMPF.

